Vaccine最新文献

Pregnant women infected with SARS-CoV2 are more likely to be hospitalized and require ventilation, compared to non-pregnant women. Although the development of the COVID-19 vaccine was regarded as a scientific breakthrough among many, the pace of development in combination with delayed and unclear recommendations for maternal vaccination led to slower vaccine uptake among this population. We explored the decision-making process for COVID-19 vaccination among pregnant and postpartum women in four countries: Brazil, Ghana, Kenya, and Pakistan through 201 in-depth interviews. A grounded theory approach was used for analysis, and a socio-ecological framework was used to synthesize emerging themes. Four levels of influence on vaccine-related attitudes and behaviors were identified: individual, interpersonal, community, and policy. Risk perception and beliefs about vaccines safety were the primary individual-level factors identified. Risk perception of the disease was a common reason for vaccine acceptance, whereas lower risk perception emerged as a reason to not vaccinate. Vaccine safety concerns, for the pregnant woman herself, her pregnancy, and her baby were common across all countries. At the interpersonal level, the influence of the male partner and peers emerged across all countries. While participants identified the partner or spouse was most influential, they also discussed the limited impact the male partner had on decision-making, particularly in Ghana, Kenya, and Pakistan. At the community-level, healthcare providers helped in allaying vaccine safety concerns, and women looked to them for their health expertise and recommendations. At the policy-level, the requirement - real or perceived - of vaccination to access services, travel, work, and education was an important factor in all countries. Vaccine decision-making is complex, multi-faceted, and context-specific. When promoting vaccination among pregnant and postpartum women, engaging influential individuals can support the successful uptake of maternal vaccination.

Introduction: Pregnant women are at increased risk of severe manifestations of COVID-19, resulting in ICU admission, mechanical ventilation, and death compared to non-pregnant women. COVID-19 vaccines were approved for use in pregnant women in early 2022 by the World Health Organization, but permissive policies toward vaccine women differed by country. As education has been associated with vaccine uptake, this study sought to examine the association between socio-economic or educational status and vaccination behaviors, including reasons for vaccination or non-vaccination among pregnant women seeking health care services in Nairobi, Kenya.

Methods: This study administered a survey to pregnant women at the two referral hospitals in Nairobi: Aga Khan University Hospital (AKUH) and Pumwani Maternity Hospital (PMH).

Results: A total of 400 women took the survey. Pregnant women with college level education were more likely to have been vaccinated for COVID-19 compared to pregnant women without a college education. Women registered or visiting for pregnancy and delivery care from AKUH Kenya were also more likely to be vaccinated compared to women receiving care from PMH. Despite this difference in COVID-19 vaccine uptake, women from both the hospitals had similar reasons for receiving or refusing a COVID-19 vaccine. a Our findings align with previous studies that have showed that education status correlates positively with COVID-19 vaccination among pregnant women.

Discussion: To improve maternal vaccination acceptance, education status can be used as a way to segment audiences to inform messaging and other demand generation efforts.

Background: Lower rates of COVID-19 vaccination among pregnant women prompt an investigation into the underlying reasons. This study aims to explore the attitudes of pregnant women in Pakistan regarding COVID-19 vaccination decision-making and to identify the factors influencing their vaccine uptake.

Methods: A cross-sectional survey of pregnant women was conducted at two hospitals in Karachi in February-May 2024. The survey included a four-point Likert scale to evaluate 19 attitudes toward COVID-19 vaccination during pregnancy. These attitudes were later grouped into nine categories: disease risk perception, vaccine effectiveness, vaccine safety, general hesitancy (including concerns about vaccine ingredients), self-efficacy, social norms and family norms. Multivariable logistic regression was performed to identify attitudes associated with vaccine uptake.

Results: Among the 400 women surveyed, 46 % (95 %CI: 41-51) reported being vaccinated against. COVID-19. Participants with higher COVID-19 risk perception were 5.71 times more likely to be vaccinated than their counterparts (95 %CI: 2.65-12.29). Those with higher self-efficacy and those who believed their friends or family had received or would receive the vaccine, had 2.28 (95 %CI: 1.08-4.65) times and 2.19 (95 %CI: 1.03-4.65) times higher odds of being vaccinated, respectively. The adjusted odds ratio for general vaccine hesitancy was 0.37 (95 %CI: 0.18-0.78), indicating that women with higher hesitancy were 63 % less likely to be vaccinated compared to those with lower hesitancy. Furthermore, women with less support from family regarding vaccine decision-making were 69 % less likely to be vaccinated than those who received more support.

Conclusion: Attitudes associated with increased vaccination among pregnant women were higher COVID-19 risk perception, higher self-efficacy, and supportive social norms. In contrast, general vaccine hesitancy, and unsupportive family norms were significant barriers to vaccination during pregnancy. Targeted strategies are needed to address women's concerns about vaccine ingredients and promote supportive family influences, enhancing vaccine uptake in this important group.

Background: Understanding the epidemiology of SARS-CoV-2 infection in settings with limited data, especially given the dynamic nature of the virus and the reported epidemiological heterogeneity across countries, is important. We used data from the COVID-19 Vaccine effectiveness evaluation to determine factors associated with SARS-COV-2 infection among patients (≥ 12 years) with severe respiratory illness (SRI) in Kenya and Mali.

Methods: SRI was defined as acute onset (≤ 14 days) of at least two of the following: cough, fever, chills, rigors, myalgia, headache, sore throat, fatigue, congestion or runny nose, loss of taste or smell, or pneumonia diagnosis. We collected demographic and clinical characteristics of the patients, and nasopharyngeal and oropharyngeal specimens for SARS-CoV-2 testing using RT-PCR. We used a mixed effect logistic regression to determine factors associated with SARS-CoV-2 infection adjusting for age and sex while controlling for clustering by site and month of illness onset.

Results: Between July 2022 and October 2023, a total of 9941 patients with SRI were enrolled, of whom, 588 (5.9 %) tested positive for SARS-CoV-2. Compared to patients aged 12-24 years, those who were aged >64 years were more likely to have SARS-CoV-2 infection (adjusted Odds Ratio [aOR] = 1.60; 95 % Confidence Interval [95 % CI] 1.07-2.40). Additionally, SRI patients presenting with cough (aOR = 1.37; 95 % Confidence Interval [95 % CI] 1.05-1.80), sore throat (aOR = 1.56; 95 % CI 1.23-1.99), runny nose (aOR = 1.51; 95 % CI 1.18-1.94), and ear pain discharge (aOR = 2.58; 95 % CI 1.43-4.66) were more likely to have SARS-CoV-2 infection compared to those who did not. SRI patients who had HIV were also more likely to have SAR-CoV-2 infection compared to those who did not (aOR =1.32; 95 % CI 1.04-1.67).

Conclusion: Older adults and HIV patients were at increased-risk of SARS-CoV-2 infection consistent with WHO guidelines highlighting the need for targeted prevention and management strategies focused on them.

Background: A number of vaccines were recommended by many countries for pregnant persons to reduce the risk associated with COVID 19 infection in pregnancy. Despite this potential of the vaccine, uptake remains challenging among pregnant women especially in low-income countries. Hence, this study assessed the influence of some factors on the uptake of COVID- 19 vaccine among pregnant women.

Method: A structured tool which elicited information on participants' background, knowledge, attitude and the outcome of interest 'ever vaccinated for COVID-19' at any point in time were used to interview the pregnant women from three facilities in the Greater Accra Region, Ghana.

Findings: A total of 401 pregnant women were recruited consecutively from all three facilities. Most of the women were between 25 and 34 years old (55.8 %), married (75.6 %), in their third trimester of pregnancy (41.4 %) and had attained junior or senior high school education (61.1 %). The frequency of COVID-19 vaccine uptake among participants was 41.9 %. Vaccination was higher among women with a college or university education (AOR = 3.35, 95 % CI = 1.48-7.54), older women aged 35-49 years (AOR = 1.82, 95 % CI = 0.90-3.66), and women who believed the COVID-19 vaccine in pregnancy will reduce their baby's risk (AOR = 3.02, 95 % CI = 1.37-6.63).

Discussion: The study recommends the need for vaccination education campaign among pregnant women with more efforts targeted at those with low level of education and younger (below 35 years old).

Background: COVID-19 vaccine effectiveness estimates from Africa are limited. These data can guide decisions on selecting priority groups in vaccine programs. This study estimated VE for BNT162b2 and Ad26.COV2.S against COVID-19-related hospitalisation, stratified by age group, time since vaccination, and HIV-infection status for three SARS-CoV-2 surges in South Africa.

Methods: We applied a test-negative case-control design to hospitalisations for acute respiratory infections amongst members of a medical insurance plan during the delta (9 May 2021-18 September 2021), omicron BA.1 (28 November 2021-5 February 2022), and BA.4/5 (17 April 2022-28 May 2022) variant periods. All data, including vaccination history, were extracted from insurance plan claims. Logistic regression models adjusted for age, comorbidities, time since vaccination, income level and documentation of previous SARS-CoV-2 infection, were used to calculate VE.

Results: BNT162b2 was protective against COVID-19-related hospitalisation for all variant periods (VE 89.3 % (95 % CI, 85.9-91.9) for delta, reduced to 31.4 % (95 % CI, 19.1-41.9) and 22.7 % (95 % CI, 2.2-38.9) for omicron BA.1, and BA.4/5 respectively). VE estimates for Ad26.COV2·S, although lower than BNT162b2, were protective for all periods (48.8 % (95 % CI, 39.6-56.5), 19.8 % (95 % CI, 5.8-31.6), and 45.0 % (95 % CI, 29.8-57.0) for delta, omicron BA.1, and BA.4/5 respectively). Protection against severe infection was shown in those ≥60 years and younger age groups, as well as in people living with HIV (PLWH) and HIV-uninfected individuals.

Conclusion: Vaccination offered significant protection against COVID-19-related hospitalisation in PLWH and the elderly, and is therefore an effective means of reducing severe outcomes in these high-risk populations in South Africa. VE against BA.4/5 waned with time since vaccination suggesting boosters may be necessary.

Background: The African Region Monitoring Vaccine Effectiveness network (AFRO-MoVE) was established by the World Health Organization Regional Office for Africa in March 2021 to support implementation of COVID-19 vaccine effectiveness studies in the region.

Objectives: Primary goals of the evaluation were to assess how AFRO-MoVE addressed its objectives supporting regional vaccine effectiveness (VE) studies, to describe challenges and opportunities, and make recommendations to strengthen future efforts related to regional VE research.

Methods: From September 2023 through June 2024, a mixed-methods approach was employed to synthesize information from: (1) documentation provided by AFRO-MoVE; (2) a standardized study review tool; (3) an electronic stakeholder survey; and (4) a series of key informant interviews. Data were collected and exported via REDCap and summarized using Microsoft Excel. Thematic analysis was used to analyse the qualitative data. Perceived challenges were summarized together with perceived support by the network in addressing each challenge.

Results: AFRO-MoVE provided support to ten VE studies, including support for protocol development, study implementation, data management, and analysis, while also facilitating knowledge exchange and experience sharing among study implementers. While respondents reported strengthened capacity for VE studies at the national and regional levels in these areas, enrollment of SARS-CoV-2 positive cases was challenging, due to a decline in reported cases in network countries in mid-2022, when many studies were launched. These challenges contributed to a lack of published VE estimates from network study sites in time to inform vaccine policy.

Conclusion: AFRO-MoVE technical assistance and financial support was viewed positively by network members and contributed to increased capacity for conducting VE studies in the region. Publication of study results would further bolster the impact of the network. These finding underscore opportunities to enhance capacity for rapid VE generation and support preparedness for future pandemics.

Introduction: As of 24 October 2021, 128,868 laboratory-confirmed COVID-19 cases and 3550 deaths were reported from Namibia. The national COVID-19 vaccination campaign that started in March 2021 included health workers (HWs) as a priority group. The vaccines most administered were Sinopharm, AstraZeneca, Pfizer-BioNtech, and Janssen. We aimed to measure the effectiveness of COVID-19 vaccines (VE) amongst HWs against laboratory-confirmed SARS-CoV-2 infection in Namibia.

Methods: We conducted a test negative design (TND) amongst HWs from the two main hospitals treating COVID-19 patients. HWs were defined as all hospital staff over 18 years in direct or indirect contact with patients, eligible for COVID-19 vaccination. We interviewed actively recruited HWs with standardized questionnaires in-person from 25/10/2021 to 25/4/2022. The participants had to state their vaccination status, which was verified through vaccination card, vaccine registry and/or District Health Information System 2. RT-PCR testing of respiratory specimens and serological testing (Wantai and Platelia-ELISA) were conducted. We measured VE by comparing the vaccination status between RT-PCR positive and negative HWs using a multivariable logistic regression model, which was adjusted for confounders. We calculated VE = (1-odds ratio of vaccination)*100 %.

Results: We included 1201 HWs of which 322 (26.8 %) participants were fully vaccinated with a primary series against COVID-19, 62 (5.2 %) were partially vaccinated and 735 (61.2 %) were not vaccinated. In total, 1119 (93 %) participants had antibodies against SARS-CoV-2 including 637 (90 %) of the unvaccinated participants. Fifty-eight (4.8 %) participants tested RT-PCR positive for SARS-CoV-2. The Omicron variant was detected in all 13 sequenced genomes (11 BA.1.18, 2 BA.1). The estimated overall VE for full vaccination was 61.8 % (95 %-confidence interval, 9.3-83.9 %).

Conclusions: The VE results suggest that COVID-19 vaccines used in Namibia provided good protection from infections with the Omicron variant even if many participants had a SARS-CoV-2 infection before the study. Therefore, COVID-19 vaccines should be administered to risk groups such as HWs independent from previous infections.

Background: COVID-19 vaccines significantly reduce severe disease outcomes, but uncertainty remains about long-term protection. We investigated vaccine effectiveness (VE) against SARS-CoV-2 infection over extended periods in the World Health Organisation AFRO-MoVE network studies in Africa.

Methods: Participants with COVID-19-like symptoms were recruited between 2023 and 2024 for a test-negative case-control study conducted across 19-healthcare centres in Uganda. Cases were symptomatic patients with any three of cough, sore-throat, coryza, among others, and PCR-confirmed SARS-CoV-2, while controls were SARS-CoV-2 PCR-negative. Vaccination was verified from vaccination cards, hospital-records, vaccination registry and self-reporting. VE was assessed through three measures: (a) Annual - patients vaccinated in the past 12-months regardless of dose vs those vaccinated >12-months before symptom onset plus unvaccinated; (b) Absolute - patients vaccinated in the past 12-months vs unvaccinated; and (c) Relative - patients vaccinated in the past 12-months vs those vaccinated >12-months before symptom onset. VE was calculated as 1- adjusted odds ratio for three patient groups based on days since the last dose; (1) <365, (2) 7-269 and (3) 270-364 while adjusting for age, sex, calendar-time and chronic conditions. The sensitivity analysis excluded patients that were previously infected with SARS-CoV-2.

Findings: In total, 1371 patients, 56 % female were recruited. Of these, 173 were classified as cases, with 97 (56 %) fully vaccinated compared to 701 (59 %) controls, p = 0.830. The overall adjusted VE was moderate, 45 % to 59 %, and remained consistent across the annual, absolute and relative measures. Sensitivity analysis showed consistently lower VE (32 % to 38 %) across all measures.

Interpretation: The results suggest that COVID-19 vaccination provides moderate protection against symptomatic SARS-CoV-2 infection up to 12-months after the last dose and highlight the importance of up-to-date vaccinations for high-risk individuals. The lack of clear COVID-19 seasonality in this and other African settings creates a challenge to selecting the optimal timing for annual vaccination.

Introduction: The emergence of new SARS-CoV-2 variants threatens the effectiveness of global vaccination campaigns. This study examines the vaccination status and associated factors among patients presenting with COVID-19-like symptoms at 19 healthcare facilities in Uganda.

Materials and methods: A cross-sectional analysis was conducted using data collected at health facilities to evaluate the effectiveness of COVID-19 vaccines in Uganda from March 2023 to March 2024. Participants were individuals aged 12 years and older with COVID-19-like symptoms who underwent a SARS-CoV-2 qPCR test within 10 days of symptom onset. The study involved obtaining informed consent, collecting medical and vaccination histories (confirmed using vaccination cards and Ministry of Health COVID-19 database), performing physical examinations, administering a questionnaire, and taking oral/nasopharyngeal swabs for SARS-CoV-2 qPCR testing. Vaccination coverage was defined as receiving at least one vaccine dose. Logistic regression was used to identify factors associated with vaccination status.

Results: Among 1398 participants enrolled (55.4 % female), the median age was 30.0 years (IQR: 24.0-41.0). Vaccination coverage, was 66.6 %. Residing in Wakiso district compared to the Capital, Kampala was associated with a higher likelihood of vaccination (adjusted odds ratio [aOR] = 1.4, 95 % CI: 1.0-1.8, p = 0.021). Frontline and healthcare workers were more likely to be vaccinated (aOR = 5.0, 95 % CI: 3.6-7.3, p < 0.001), as were individuals with a previous COVID-19 diagnosis (aOR = 2.4, 95 % CI: 1.6-3.9, p < 0.001).

Conclusions: Our results underscore the need for targeted public health messaging and support to promote vaccination, especially among non-healthcare workers. Addressing these gaps is crucial for maintaining high vaccination coverage and mitigating the impact of new SARS-CoV-2 variants on the population.